Very Computer

Hello everyone

Whilst not specifically an AIX issue, I'd appreciate anyones input on
my
situation.

I'm currently looking at purchasing an enterprise storage solution to
service initially a pair of S80's running AIX4.3.3 and HACMP.  This
will grow to about 4TB and also service other platforms, namely HP/UX,
NetWare 4&5 and NT4/2000.

We have been looking at IBM ESS (Shark), HDS 9600 and EMC's offerings.
 I'd appreciate any good/bad experiences any one has had with these
system.  

Some of my specific questions are:

1.  Is EMC really worth the extra?
2.  Does IBM's flash copy and Remote copy work in real work
environments?
3.  Does HDS's flash copy and Remote copy work?
4.  As we will be using HACMP, is LVM mirroring across 2 storage units
better then using the units own Remote copy service?  We've had
conflicting advice in this.

Thanks for you time in reading and hopefully answering too :)

Steven

It depends what do you need. If you have extra money to spend, get EMC.
Since EMC is still the industry leader for now.

Quote:> 2.  Does IBM's flash copy and Remote copy work in real work
> environments?

Flash copy and remote copy might not be ready for Open systems yet.
Double check with IBM.

Quote:> 3.  Does HDS's flash copy and Remote copy work?
> 4.  As we will be using HACMP, is LVM mirroring across 2 storage
units
> better then using the units own Remote copy service?  We've had
> conflicting advice in this.

Don't know what you try to accomplish there. But I will perfer not to
use LVM to mirror your storage systems. Let it to the hardware.
However, if you need avaliabilties on storage systems, there maybe are
better solutions in SAN.

Just my 2 cents.

Elli

Sent via Deja.com
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HACMP + EMC = headache.

You WILL have problems if you use HACMP with EMC systems. Guaranteed.  It
just doesn't work.  Ghost disks, failed resource takeovers, all sorts of
fun.

IBM is...unmotivated...to make HACMP work well with EMC disks, and EMC is
apparently unable to help.

Forget about redundant data paths (i.e. EMC PowerPath or IBM's Data Path
Optimizer, aka Subsystem Device Driver) if you're using HACMP - it's not
supported.

If you want to make your HACMP cluster work well, you're best off sticking
with SSA.

If you must have HACMP and you must have a storage server, go with the
ESS. IBM is orders of magnitude more motivated to make HACMP play nice
with ESS than it ever will be with EMC.

--
Scott Ellerman
The opinions expressed above are solely my own, and not those of Nortel
Networks or IBM.

Hi There,

Regarding EMC and HACMP I must respectfully disagree.

HACMP (classic and ES) works fine with EMC on our systems, and its even
easier with PowerPath.

Where things get seriously interesting is when you try to use EMC's
splittable mirror software "Timefinder".

Don't even toy with the remotest possibility of trying to make this work
within an HA cluster.

It is possible to use the mirror ('BCV') devices on different nodes in the
same SP frame for example, but the node where you varyon the BCV must not be
in the same logical HA cluster as the Standard disks.

I should add that unless you're:

i) A mean script writer and
ii) A handy C programmer and
iii) A pretty useful ODM hacker, you might struggle.

It took me 18 months to build our solution...

Regards,

Nick Buckley,
Senior AIX Systems Administrator,
NCM,
Cardiff,
United Kingdom

(Please note: all newsgroup offerings are made in a personal
capacity and in no way are the responsibility of my employer)

p.s. Did you know that "AIX Operating System" is an anagram of "Mega *
partitions" !!!

EMC Powerpath and ESS both work in an HACMP env, however EMC is never
going to be supported
by IBM.   IBM will help with HACMP failover problems, etc; but if the
problem is found to be EMC
IBM can only do so much.

HACMP has supportted SDD in concurrent access mode for some time, but if
you want to use
SDD in a cascading or rotating environment, I would wait a little longer
(support was announced last Fri)
Unless you are just the Bleeding Edge kind of guy

--
C. DeVille
IBM  AIX/HACMP Certified Specialist
These opinions are my own.
Any suggestions are "Use At Your Own Risk"

Quote:> HACMP has supportted SDD in concurrent access mode for some time, but if
> you want to use
> SDD in a cascading or rotating environment, I would wait a little longer
> (support was announced last Fri)
> Unless you are just the Bleeding Edge kind of guy

> [snip]
> --
> C. DeVille
> IBM  AIX/HACMP Certified Specialist
> These opinions are my own.
> Any suggestions are "Use At Your Own Risk"

Heh, lucky you, Chris.  Everyone, listen to this guy before you listen to
me about HACMP/DASD issues.  He knows a lot more about it than I do.

Scott

Hello all

Thanks for all the replies - keep em coming!!

One thing, what is SDD?

Steven

New update on the ESS/SDO front from Dec 15.

--
Doing AIX support was the most monty-pythonesque
activity available at the time.

Yep, that's what I get for not checking announcement letters.  Love your .sig
by the way.

S.